U.S. Pat. No. 7,405,214 (issued Jul. 29, 2008) discloses a compound of formula (I)
also referred to as RX-3117, fluorocyclopentenylcytosine or 4-amino-1-((1S,4R,5S)-2-fluoro-4,5-dihydroxy-3-hydroxymethyl-cyclopent-2-enyl)-1H-pyrimidin-2-one. U.S. Pat. No. 7,405,214 also discloses an 11-steps total synthesis of RX-3117 from D-ribose and the synthesis uses an expensive catalyst which poses a challenge for implementation in plant production.
U.S. Pat. No. 9,150,520 (issued Oct. 6, 2015) discloses a short route for the preparation of RX-3117 through (3R,4R,6aR)-tert-butyl-(5-fluoro-2,2-dimethyl-6-trityloxymethyl-4,6a-dihy-dro-3aH-cyclopenta[1,3]dioxol-4-yloxy)-diphenyl-silane to 4-amino-1-(3aS,4S,6aR)-5-fluoro-2,2-dimethyl-6-((trityloxy)methyl)-4,6a-d-ihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl)pyrimidin-2(1H)-one. The synthesis requires the intermediates to be isolated in each step. Thus, the process is unsatisfactory for scaled up production of the final product due to time and cost constraints. Therefore, there is a need to provide an improved process, for example by reducing the number of steps and/or removing the need to purify each intermediate.